Add remote maintenance user

authorized_keys

@@ -0,0 +1 @@
+ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILZKBTf7HdsZDJDwblnROAaGZDIWi/jWNwGjrih8UPuY kalle@kalle-laptop

systems/base.nix

@@ -33,6 +33,16 @@
       "flakes"
     ];
 
+    # Set up user for remote admin
+    users.users."maintenance" = {
+      isNormalUser = true;
+      group = "maintenance";
+      extraGroups = [ "wheel" ];
+      openssh.authorizedKeys.keyFiles = [ ../authorized_keys ];
+    };
+
+    users.groups."maintenance" = {};
+
     # Enable mDNS for `hostname.local` addresses
     services.avahi.enable = true;
     services.avahi.nssmdns = true;